In-wheel motor cooling apparatus and method

Abstract

An in-wheel motor cooling apparatus may include: a braking data calculation part configured to calculate a braking severity related to a braking data of a braking device of a driving state; a motor temperature measurement part configured to measure a temperature and a temperature change of the in-wheel motor of a driving-finished state; a driving controller configured to start driving of a water pump, in the driving-finished state, when the braking severity and the temperature change is above a predetermined standard; and a cooling flow control part configured to determine a cooling flow rate of the water pump in real-time based on a temperature of the in-wheel motor, when the driving of the water pump is started.

What is claimed is: 
     
         1 . An in-wheel motor cooling apparatus, comprising:
 a braking data calculation part configured to calculate a braking severity related to a braking data of a braking device of a driving state;   a motor temperature measurement part configured to measure a temperature and a temperature change of the in-wheel motor of a driving-finished state;   a driving controller configured to start driving of a water pump, in the driving-finished state, when the braking severity and the temperature change is above a predetermined standard; and   a cooling flow control part configured to determine a cooling flow rate of the water pump in real-time based on a temperature of the in-wheel motor, when the driving of the water pump is started.   
     
     
         2 . The in-wheel motor cooling apparatus of  claim 1 , wherein the driving state is a key-on state in which the vehicle is turned on, and wherein the driving-finished state is a key-off state in which the vehicle is turned off. 
     
     
         3 . The in-wheel motor cooling apparatus of  claim 2 , wherein the braking data calculation part is configured to calculate the braking severity based on the braking data of the vehicle including a braking hydraulic pressure, a braking period, a driving speed and a heat dissipation coefficient of the vehicle in the key-on state. 
     
     
         4 . The in-wheel motor cooling apparatus of  claim 1 , wherein:
 when the temperature of the in-wheel motor is greater than an emergency cooling temperature, the cooling flow control part determines the cooling flow rate of the water pump as an emergency cooling flow rate that is a maximum flow amount of the water pump; and   wherein the emergency cooling temperature is less than a predetermined motor management temperature of the in-wheel motor by a first temperature difference.   
     
     
         5 . The in-wheel motor cooling apparatus of  claim 4 , wherein:
 when the temperature of the in-wheel motor is greater than a basic cooling temperature and less than or equal to the emergency cooling temperature, the cooling flow control part determines the cooling flow rate of the water pump as a basic cooling flow rate less than the emergency cooling flow rate; and   wherein the basic cooling temperature is less than the motor management temperature by a second temperature difference.   
     
     
         6 . The in-wheel motor cooling apparatus of  claim 5 , wherein, when the basic cooling flow rate is less than the cooling flow rate during the driving of a vehicle, the cooling flow control part adjusts the basic cooling flow rate to be equal to the cooling flow rate during the driving. 
     
     
         7 . The in-wheel motor cooling apparatus of  claim 6 , wherein, when the temperature of the in-wheel motor is less than or equal to the basic cooling temperature after the driving of the water pump is started, the driving controller stops the driving of the water pump. 
     
     
         8 . An in-wheel motor cooling method, comprising:
 calculating a braking severity of the vehicle during driving by an in-wheel motor cooling apparatus, when a vehicle is turned off;   measuring a temperature and a temperature change of the in-wheel motor of the vehicle of a key-off state in which the vehicle is turned off, by the in-wheel motor cooling apparatus;   controlling driving of a water pump, in the key-off state, based on the calculated braking severity and the measured temperature change of the in-wheel motor, the in-wheel motor cooling apparatus; and   controlling a cooling flow rate of the water pump in real-time based on a temperature of the in-wheel motor, by the in-wheel motor cooling apparatus, when driving of the water pump is started.   
     
     
         9 . The in-wheel motor cooling method of  claim 8 , wherein calculating the braking severity further comprises:
 calculating braking energy with a braking data of the vehicle including a braking hydraulic pressure, a braking period, a driving speed, and a heat dissipation coefficient, in a driving state at key-on of the vehicle.   
     
     
         10 . The in-wheel motor cooling method of  claim 9 , wherein controlling the driving of the water pump further comprises:
 starting the driving of the water pump if the braking energy is higher than a predetermined specific criterion and the temperature change of the in-wheel motor is greater than the predetermined specific criterion.   
     
     
         11 . The in-wheel motor cooling method of  claim 10 , wherein controlling the cooling flow rate further comprises:
 determining the cooling flow rate of the water pump as an emergency cooling flow rate that is a maximum flow amount of the water pump, when the temperature of the in-wheel motor is greater than an emergency cooling temperature,   wherein the emergency cooling temperature is less than a predetermined motor management temperature of the in-wheel motor by a first temperature difference.   
     
     
         12 . The in-wheel motor cooling method of  claim 11 , wherein controlling the cooling flow rate further comprises:
 determining the cooling flow rate of the water pump as a basic cooling flow rate less than the emergency cooling flow rate, when the temperature of the in-wheel motor is greater than a basic cooling temperature and less than or equal to the emergency cooling temperature,   wherein the basic cooling temperature is less than the motor management temperature by a second temperature difference.   
     
     
         13 . The in-wheel motor cooling method of  claim 12 , wherein determining the cooling flow rate as the basic cooling flow rate further comprises:
 adjusting the basic cooling flow rate to be equal to the cooling flow rate at the key-on, when the basic cooling flow rate is less than the cooling flow rate at the key-on of the vehicle.   
     
     
         14 . The in-wheel motor cooling method of  claim 13 , wherein controlling the driving of the water pump further comprises:
 stopping the driving of the water pump, after the driving of the water pump is started, when the temperature of the in-wheel motor is less than or equal to the basic cooling temperature.   
     
     
         15 . An in-wheel motor cooling method, comprising:
 calculating a temperature increase amount of the in-wheel motor based on an initial temperature of a braking device after a key-off state of a vehicle;   calculating a maximum reached temperature of the in-wheel motor based on the initial temperature and the temperature increase amount after a key-off of the in-wheel motor;   calculating a cooling target temperature of the in-wheel motor based on a difference value between the maximum reached temperature and a limit temperature of the in-wheel motor; and   measuring a real-time temperature of the in-wheel motor and driving a water pump until the real-time temperature is below the cooling target temperature.   
     
     
         16 . The in-wheel motor cooling method of  claim 15 , wherein a temperature increase amount of the in-wheel motor is proportional to the initial temperature of the braking device. 
     
     
         17 . The in-wheel motor cooling method of  claim 15 , wherein driving the water pump further comprises:
 calculating a temperature difference between an ambient air temperature and the cooling target temperature; and   controlling a cooling flow rate of the water pump based on the calculated temperature difference.   
     
     
         18 . The in-wheel motor cooling method of  claim 17 , wherein controlling the cooling flow rate further comprises:
 determining the cooling flow rate of the water pump as a basic cooling flow rate when the temperature difference between the cooling target temperature and the ambient air temperature is more than a specific criterion; and   determining the cooling flow rate as an emergency cooling flow rate when the temperature difference is less than the specific criterion,   wherein the emergency cooling flow rate is more than the basic cooling flow rate.   
     
     
         19 . The in-wheel motor cooling method of  claim 18 , wherein calculating the cooling target temperature further comprises:
 determining a resulting value obtained by subtracting the difference value from the initial temperature of the in-wheel motor as the cooling target temperature, when the difference value between the maximum reached temperature and the limit temperature is calculated.   
     
     
         20 . The in-wheel motor cooling method of  claim 15 , further comprising:
 maintaining the maximum reached temperature of the in-wheel motor below the limit temperature of the in-wheel motor.